Dark Energy - The Research

Submitted by mike on September 12, 2011 - 10:02pm

Dark energy is the dominant component in the universe, yet there are currently no compelling explanations for its existence or its distribution. However, KIPAC scientists along with many others in the astrophysics and cosmology community are generating a suite of techniques and observational tools that will greatly enhance our understanding of dark energy.

These techniques are based on several different observable phenomena throughout the universe, including the distribution of galaxies on very large scales; the density and distribution of galaxy clusters detected through x-rays, gravitational lensing, and distortions in the cosmic microwave background radiation; the apparent luminosity of Type Ia supernovae, which can be used for measuring vast distances across space; and the distortion of images of background galaxies due to the bending of light as it passes through the intervening dark matter. By applying these techniques to existing data sets and conducting computational studies based on cosmological simulations, researchers are gaining a more robust understanding of dark matter.

KIPAC scientists are actively involved in two highly sensitive ground-based telescope projects that will be able to more carefully probe the nature of dark energy than previous instruments. The first is the Dark Energy Survey (DES). This collaboration is building a 570-megapixel camera to mount on the Blanco four-meter telescope at Cerro Tololo Inter-American Observatory in the Chilean Andes. The second is the Large Synoptic Survey telescope (LSST) collaboration, which is designing and building a 3.2-gigapixel camera to mount on a new telescope that will be sited on the El Peñón peak of Cerro Pachón, also in Chile. The DES is slated for completion in 2012 and LSST is expected to be operational by the end of the decade.

In addition to these telescope-based projects, KIPAC scientists are also probing dark energy using the Planck Satellite, which is providing the most accurate maps of the cosmic microwave background radiation (CMB) to date, and by studying galaxy clusters, biggest gravitationally bound structures in the universe and the most recent ones to form, despite the accelerating expansion of the background spacetime.